4 Pack - SMR103C-YZZ #5 LD (3 x 10 x 4 mm) Ceramic Ball Bearing Inside Diameter: 3, mm Outside Diamater: 10, mm Width: 4 mm Bearing Material: Stainless Steel 440C, Ball Material: Ceramic SI3N4, ABEC#5/ISOP5 Enclosure: Two Shield, Lube: Lube Dry